wsbca said:
I'm not convinced that the brake pedal pressure is a transparent linear translation into a perfect simulation of Eco mode. Yes, braking does result in regen, but I think there's brake engagement as well, where if you are in Eco and just let off the accelerator you get the regen (and the slowing) without even moving your foot. Yes, in Eco you can feather the accelerator to avoid being slowed by the regen, but I think feathering the brake in D is not as effective/precise, as far as faking eco-ish regen. Not sure I'm explaining it well.
I think you have it just about right. Using the brake pedal gives some regen (if the battery isn't cold or full) and some friction brakes and it is hard to tell how much of the latter is being applied. Using the increased regen in Eco (or B mode if you have it) can be a more efficient way to slow down as needed.
Eco allows more efficient driving in several other ways. Eco limits the heater output (but not on defrost setting!). If that prevents it from heating up as quickly as needed then it might help to use D for a bit then switch to Eco after the heater is warmed up. This is a bigger deal for the S model than the SV/SL models that have a heat pump.
Also, the Eco setting is power mapped, versus the acceleration mapped D. So, in Eco if you hold the A pedal in the same position it will give you the same power. This makes it
much easier to control speed. It also allows one to hold a zero power position that is about the same as coasting. I'd venture to guess that nearly all LEAF hypermilers use Eco because of easier and more precise speed control.
It is worth mentioning that it is more efficient to coast (at typical driving speeds, not true at terminal velocity) than to use regen brakes
*. And, short of shifting to neutral, it is much, much easier to coast in Eco than in D. The efficiency progression is something like this: slow gradually by coasting > slow using regen braking > slow using friction braking.
In general you want to maintain a steady speed and anticipate future slowing or stops by coasting, where it is safe to do so, then adding a bit of regen using D, then adding more regen using Eco, then adding more regen using the brake pedal lightly and finally using friction brakes to stop. It also helps efficiency a great deal to accelerate gently and that is also
much easier to do in Eco.
The only time that D is helpful is when using cruise control (the S model doesn't have it) on undulating terrain. Then less regen braking will be used when going downhill in cruise in D than in Eco. But the energy savings is pretty trivial most of the time.
Like some other mountain drivers here, I adjust my speed using coasting, D, Eco, and the brake pedal as needed — I consider it kind of a game. But only when traffic conditions permit, of course. [B mode would be very helpful but I don't have it on my older car.]
For more on efficient driving I suggest taking a look at
Stoaty's Guide to Energy Efficient Driving of the Leaf.
* Why? Because regen is quite inefficient in energy recapture and storage in the battery. Better than the 100% loss to heat with friction brakes but much less efficient than coasting at moderate speeds.
